Grinding-mill



(No Moden) I J. STEVENS.

Grinding Mill.

NO. 240,282. patenlid April 19,1881..

o 'o e' "mll" Wi il l N'PEI'ERS. PHOTD-UTHOGHFnE-R, WASHINGTON, D (DAUNITED STATES PATENT OFFICE.

JOHN STEVENS, OF NEENAH, WISCONSIN.

GRlNDlNG-IVHLL.

SPECIFICATION forming part of Letters Patent No. 240,282, dated April19, 1881.

Application tiled December 3, 1880. (No model.)

To all whom it may concern:

Be it known that I, J ORN STEVENS, of Neenah, in the county of Winnebagoand State ot' Wisconsin, have invented certain new and usefulImprovements in Grinding- Mills, of

which the following is a specification.

1n Letters Patent of theUnited States granted to me on the 3d day ot'August, 1880, and numbered 230,834, l havedescribedand claimed adjustingmechanism applied to the sliding bearings of a yielding concave orroller, so constructed and operating that while the bearings arepermitted to yield away from the bearings of the conversegrinding-surface against springpressure, the absolute limit of theirretreat therefrom or of their advance thereto ward may be varied atwill.

My present invention relates to improvements in the adjusting mechanismdescribed in said Letters Patent 5l and it consists in shortening thecentral screws therein recited, so that they screw into, but do not passthrough, the movable blocks, and in providing the spindle of each ofsaid screws with a fixed collar, which comes against the outer end ofthe corresponding hollow screw and forms a stop to the inward movementot' the block.

In the drawings, Figure 1 is a plan view of a roller-mill embodying myinvention. Fig. 2 is a side elevation, partly in section, to show theoperation of the device; Fig. 3, a section transversely through one ofthe sliding blocks, on the line w :l: of Fig. 2, and Fig. 4 amodification.

Supported upon a strong frame, A, of any approved construction for thepurpose, are stationary blocks a, which form bearings for the roller B,and other sliding blocks, c, which receive the gudgeons of the yieldingroller C. By means of gearing, such as is usual in this class ofmachines, the rollers are caused to revolve either toward or away fromeach other, and at such relative surface-speeds as may be necessary ordesirable.

The hollow adjusting-screws E (described in my aforesaid patent) passthrough the exterior frame-work, or through lugs d projecting therefrom,so that their inner ends may come into the path of the yielding blocksand posi- 5o tively stop the retreat of the latter at a point determinedby the adjustment of said screws.

Encircling these screws are the coiled springs e, bearing at one endagainst the blocks, andv pressing them and the roll which they carryinward toward the opposite roll, and at the other end seated againstadjustable nuts'e upon the screws, whereby their stress may be increasedor decreased whenever desirable. Through the hollow screws pass thesmooth spindles of long screws F, which, at their outer ends, areprovided with a hand piece or wheel, whereby they can be readily turned,and at their inner ends are threaded into sockets in the sliding blocks,the depth of said sockets being sufficient to allow a proper range ofadjustment.

Fast to the spindles of the long` screws, in such position as to bearagainst the head or outer end of the hollow screws as the blocks arepressed in by the spring, are collars or stops f, which limit the inwardmovement ofthe long screws, but afford no obstacle to their outwardmovement when the blocks are, from any reason, caused to yield.

With this construction it is evident that the limit to which theyielding roller can approach the other, or the normal distance betweenthe grinding-surfaces, will be determined by the distance between thesliding blocks and the collars f on the long screws, and thatadjustments of this limit will be made by taking up or letting out theblocks by mea-ns of said screws, so that the collars may stop the rollfarther from or nearer to the other.

As a modification the hollow screws may be omitted and the collar uponthe long screw arranged to come directly in contact with the exterior ofthe lug d, as in Fig. 4. The coiled springs in this case will directlyencircle the long screw, and may either extend from the lug to theblock, in which event they will be only incidentally adjustable instress, or may be stopped short of the blocks by a nut, e2, on thescrew. The latter arrangement is prefera ble, since it permits thestress of the spring to be adjusted independent of the adjustment of thescrew, and to remain constant, notwithstanding the taking up or lettingout of the blocks.

To prevent the rolls from being jammed hard against each other bycarelessness on the part of the attendant in changing the adjustment,

IOO

I provide guard-screws G, which are threaded through the stationaryblocks and can be set to positively stop the approach of the slidingblocks and the roll mounted therein at any desired distance from theother roll. These will limit the range within which adjustments can bemade by the attendant by means ofthe devices at the front of themachine, while permitting entire freedom ot' adjustment within thatrange.

A concave may be mounted in the sliding blocks and controlled, as to itshorizontal adjustment, by the devices above described, as will beunderstood by reference to my former Letters Patent, hereinbeforementioned and I consider such an application as within the principle ofmy invention.

I claiml. The combination ofthe sliding blocks, the screws passingthrough lugs on the frame and threaded into such blocks, the collars orstops fast upon the spindles of said screws exterior to the lugs, andthe springs which press the slidin g blocks and the mecha-n ism carriedthereby toward the converse mechanism.

2. lhecolnbinaton of the sliding blocks, the screws passing through lugson the frame and threaded into such blocks, the collars or stops uponthe spindles ofthe screws exterior to the lugs, and theadjustable springs encircling said screws and pressing the sliding blocks and themechanism carried thereby toward the converse mechanism.

3. The combination of theslidingblocks,the hollow screws threaded intolugs on the frame andV serving as stops tolimit the retreat of saidblocks, the long screws passing through said hollow screws and threadedinto the sliding blocks, the collars or stops upon the spindles of thelong screws, arranged to come in contact with the heads of the hollowscrews, and springs pressing the sliding blocks and the roll or concavecarried thereby toward the converse grinding-surface.

4. The combination of the sliding blocks, the hollow screws threadedinto lugs on the frame and servin g as stops to limit the retreat ot'said blocks, the long screws passing through the hollow screws andthreaded into the sliding blocks, the collars or stops upon the spindleof 5ov the long screws, arranged to come in contact with the heads ofthe hollow screws, springs encircling said screws and pressing thesliding blocks and the mechanism carried thereby toward the conversemechanism, and nuts for adjusting the stress of'the springs.

5. The combination, with the spring-pressed sliding blocks, and with thcscrews by which the limit ot' their advance is adjustably determined,ot' guard-screws threaded into and passing through the stationaryblocks, to limit the range of such adjustment.

6. lhe combination, with the spring-pressed sliding blocks, and with thescrews by which the limits of their advance and vretreat are adjustablydetermined, ol' the guard screws threaded into and passing through thestationary blocks to limit the range within which said adjustments maybe made, for the purpose speci tied'.

JOHN STEVENS.

Witnesses:

JOHN R. DAVIS, Jr., JOSEPH G. PARKINsoN.

